Alex Danielsen
Husqvarna
B Class
So I went out riding and playing with the settings again.. But before I left I lowered the green zone to 3 to get my cruising AFR's closer to 14.5, and the yellow zone to 2.5 to get AFR's up between 13.2-13.5 where best power is found (thanks roger04 for all this valuable info). I also lowered the yellow/blue to 1.5 and red/blue to 3.5 to see if that would help with the rich stumbling issue/transition. And off I went.. Weather was dry and around 10 degrees C.
Pretty much as soon as I was out of my driveway and started accelerating through the gears, the rich stumbling issue was back and worse then before. I figured I would ride on a bit to ensure the engine was properly warm, but the issue persisted and the stumbling happened almost every time I accelerated quickly through the gears. So I figured I was adjusting the wrong way in the transition zones, so I turned the yellow/blue way up to 7 and the red/blue to 7 as well. This was much better and no matter how hard I treated the throttle, I couldn't induce the rich stumbling. However, it also made the engine and throttle response feel more sluggish... Not what I wanted, but I figured there must be a happy medium in there somewhere..
I had a feeling it was the yellow/blue zone that was the culprit, so I decided to leave the red/blue alone and started adjusting the yellow/blue down by half a point at a time. With every adjustment downwards, the throttle response would get better and better and the engine feel less and less sluggish in the low rpms, and still no rich stumbling issue. When I got to 5 on the yellow/blue the great throttle feeling from stock settings had pretty much been restored, and I only had the rich stumbling appear once right when I took off after adjusting, but I could not make it happen again no matter how hard I tried. So for now I decided to leave the yellow/blue on 5 as that seems close to the happy medium. I might try lowering it to 4.5 on next ride, just to see if that will work too..
When doing all these acceleration runs I had noticed a couple of things.. I needed to add a little to the yellow zone rather then lowering it to keep a consistent 13-13.5 AFR's under acceleration, so I ended up with a yellow setting of 3.5 which would consistently keep the AFR's just there. I also noticed that when cruising in a lower gear and then whacking the throttle open, the AFR's would lean half a point for a split second, but then immediately return to the desired 13-13.5 range and then slowly go lower as the revs would increase. It could not be felt in any way, I only noticed it from watching the AFR meter, and the acceleration would feel instant and quick. And that feature seemed to work well with having the red/blue zone adjusted up to 7, as no matter how I accelerated (normally, pretty quick or full throttle) the AFR's would stay just above 13, and only starting to go down as full throttle was applied AND revs would go above 5000, to finally go down to 12 at full throttle and near max revs. Which I think is pretty ideal for a normally aspirated engine, and the acceleration feels very strong and linear.
My cruising AFR's were still a bit lower then I would like, so I ended up adjusting the green zone down to 2, which would give a nice 14-14.5 cruising AFR's. Interestingly though, I noticed that once speed goes past 105 km/h (or 68 mph I think) the cruising AFR's would go down a little bit to maybe 13.5, and I attributed that to the increased wind resistance which would make the engine work harder and therefore move the fueling from green zone to yellow zone. And as soon I as I lowered my cruising speed 5-10 km/h the AFR's would go up to 14.5 again.. Food for thought when doing long distance cruising..
I also tried numerous times to pull the clutch and dump the throttle during all kinds of acceleration situations to see if I could make the engine stall, but it didn't happen once. Every time it would just immediately go down to a rock steady 1600 rpm idle, also when doing it during a rich stumble moment when the EJK was trying to sort itself. I have, as mentioned in last post, never had any stalling issues with my bike to begin with, so bear that in mind.. I also tried some slow technical forest riding at some point, and I actually managed to stall the bike during that until I realized it was in second gear instead of first, so I counted that out.. I did notice when doing that slow technical riding, that when its doing idle or just above in first gear and basically just pulling itself along, the AFR's would be down at 12.5 - 13 so definitely on the rich side, but I also feel that it prevents the engine from bogging and makes it so nice and tractable.
So that was yesterdays ride and experiences and I was quite happy with how the bike and fueling felt at the end of it. There might still be room for improvement so I will keep playing for as long as I have the SAFR lambda tool available. I noticed that many of you have the red/blue zone adjusted down a lot and some all the way down to 0.5 which is quite opposite of me, so I will most likely try that too to see what that does to ride ability and AFR's..
Just to recap, my final settings were: 2 - 3.5 - 0.5 - 0.5 - 5 - 7
Alex.
Pretty much as soon as I was out of my driveway and started accelerating through the gears, the rich stumbling issue was back and worse then before. I figured I would ride on a bit to ensure the engine was properly warm, but the issue persisted and the stumbling happened almost every time I accelerated quickly through the gears. So I figured I was adjusting the wrong way in the transition zones, so I turned the yellow/blue way up to 7 and the red/blue to 7 as well. This was much better and no matter how hard I treated the throttle, I couldn't induce the rich stumbling. However, it also made the engine and throttle response feel more sluggish... Not what I wanted, but I figured there must be a happy medium in there somewhere..
I had a feeling it was the yellow/blue zone that was the culprit, so I decided to leave the red/blue alone and started adjusting the yellow/blue down by half a point at a time. With every adjustment downwards, the throttle response would get better and better and the engine feel less and less sluggish in the low rpms, and still no rich stumbling issue. When I got to 5 on the yellow/blue the great throttle feeling from stock settings had pretty much been restored, and I only had the rich stumbling appear once right when I took off after adjusting, but I could not make it happen again no matter how hard I tried. So for now I decided to leave the yellow/blue on 5 as that seems close to the happy medium. I might try lowering it to 4.5 on next ride, just to see if that will work too..
When doing all these acceleration runs I had noticed a couple of things.. I needed to add a little to the yellow zone rather then lowering it to keep a consistent 13-13.5 AFR's under acceleration, so I ended up with a yellow setting of 3.5 which would consistently keep the AFR's just there. I also noticed that when cruising in a lower gear and then whacking the throttle open, the AFR's would lean half a point for a split second, but then immediately return to the desired 13-13.5 range and then slowly go lower as the revs would increase. It could not be felt in any way, I only noticed it from watching the AFR meter, and the acceleration would feel instant and quick. And that feature seemed to work well with having the red/blue zone adjusted up to 7, as no matter how I accelerated (normally, pretty quick or full throttle) the AFR's would stay just above 13, and only starting to go down as full throttle was applied AND revs would go above 5000, to finally go down to 12 at full throttle and near max revs. Which I think is pretty ideal for a normally aspirated engine, and the acceleration feels very strong and linear.
My cruising AFR's were still a bit lower then I would like, so I ended up adjusting the green zone down to 2, which would give a nice 14-14.5 cruising AFR's. Interestingly though, I noticed that once speed goes past 105 km/h (or 68 mph I think) the cruising AFR's would go down a little bit to maybe 13.5, and I attributed that to the increased wind resistance which would make the engine work harder and therefore move the fueling from green zone to yellow zone. And as soon I as I lowered my cruising speed 5-10 km/h the AFR's would go up to 14.5 again.. Food for thought when doing long distance cruising..
I also tried numerous times to pull the clutch and dump the throttle during all kinds of acceleration situations to see if I could make the engine stall, but it didn't happen once. Every time it would just immediately go down to a rock steady 1600 rpm idle, also when doing it during a rich stumble moment when the EJK was trying to sort itself. I have, as mentioned in last post, never had any stalling issues with my bike to begin with, so bear that in mind.. I also tried some slow technical forest riding at some point, and I actually managed to stall the bike during that until I realized it was in second gear instead of first, so I counted that out.. I did notice when doing that slow technical riding, that when its doing idle or just above in first gear and basically just pulling itself along, the AFR's would be down at 12.5 - 13 so definitely on the rich side, but I also feel that it prevents the engine from bogging and makes it so nice and tractable.
So that was yesterdays ride and experiences and I was quite happy with how the bike and fueling felt at the end of it. There might still be room for improvement so I will keep playing for as long as I have the SAFR lambda tool available. I noticed that many of you have the red/blue zone adjusted down a lot and some all the way down to 0.5 which is quite opposite of me, so I will most likely try that too to see what that does to ride ability and AFR's..
Just to recap, my final settings were: 2 - 3.5 - 0.5 - 0.5 - 5 - 7
Alex.